An erasing device which erasing the color of an image on a sheet is provided. The sheet subjected to erasing by the erasing device is reused through repeating image forming using a color material which has erasability and image erasing on the sheet.
As for the reused sheets, corner fold sheets in which the corner of the paper edge is folded over of the sheet may be mixed in among the sheets loaded on a paper feeding unit of the erasing device. Such corner folding of the sheet, for example, may occur when repeated process of erasing causes curling at the paper edge, and when the sheet is loaded on the paper feeding unit of the erasing device, the corner of the curled paper edge may become folded.
The corner fold may hinder normal conveyance of the sheet and further preclude sufficient decolorizing for an image on the paper surface covered by the corner fold portion.